Method of making sealed switches



1, 1965 w. JUPTNER 3,182,382

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United States Patent 3,182,382 METHOD OF MAKING SEALED SWITCHES WilhelmJuptner, Costa Mesa, Caliii, assignor to C. P. Clare & Company, Chicago,Ill., a corporation of Delaware Original application Aug. 14, 1957, Ser.No. 678,236, now Patent No. 3,033,956, dated May 8, 1962. Divided andthis application Sept. 7, 1961, Ser. No. 136,590 9 Claims. (Cl.29155.55)

This invention relates to a method of making switching devices and, moreparticularly, to a method of assembling a sealed switch unit having apivotally mounted armature. The present application is a division of acopending application Serial No. 678,23 6, filed August 14, 1957, nowPatent No. 3,033,956.

One object of the present invention is to provide a new and improvedmethod of assemblying sealed switch units.

Another object is to provide a method of making a sealed switch unithaving a magnetic armature pivotally mounted on one of a plurality ofmagnetic terminals sealed Within a dielectric housing.

Briefly, the above and further objects are realized in accordance withthe present invention by providing a switching unit comprising as itsprincipal elements a balanced, pivotally mounted armature and two ormore electrically conductive terminal members which extend from theswitching unit, at least two of the terminals being ferromagnetic so asto function as pole pieces as well as electric terminals. This sealedswitch is constructed by sealing one magnetic terminal in one end of anelongated dielectric housing, inserting the armature and pivotallymounting it on the one terminal, and then mounting another terminal inthe open end of the housing and sealing this other terminal in thehousing.

The invention, both as to its organization and method of operation,together with further objects and advantages thereof, will best beunderstood by reference to the following detailed description taken inconnection with the accompanying drawings, in which:

FIG. 1 is a side elevational view, partially in section, of a relayembodying certain aspects of the present invention;

FIG. 2 is a perspective View showing the switching unit of the relayillustrated in FIG. 1;

FIG. 3 is a fragmentary perspective view of a switching unit embodyingthe present invention;

FIGS. 4 and 5 are fragmentary side elevational views of switching unitsembodying other aspects of the present invention;

FIG. 6 is a fragmentary side elevational view of the upper portion of arelay embodying certain aspects of the present invention; and

FIG. 7 is a side elevational view of a relay switching unit embodyingcertain aspects of the present invention.

Referring now to the drawings and more particularly to FIG. 1 thereof,there is shown a complete relay 10 which comprises as its principalelements a generally cylindrical housing or can 12 in which is. mounteda control Winding or coil 13 and a hermetically sealed switching unit orcartridge 14. In the unit 14, a ferromagnetic electrically conductiveterminal and heel piece 15 protrudes from the top of a hermeticallysealed glass housing 16 from the bottom of which extend two terminalmembers 17 and 18. The terminal 17 is ferromagnetic so that it alsofunctions as a heel piece. The members 15 and 17 thus cooperate with thecan 12 and a tubular ferromagnetic sleeve 21 to provide a stator havingan air gap in which a balanced ferromagnetic and electrically conductivearmature 22 is pivotally mounted for selectively connecting the terminalmember 15 to either the terminal member 17 or the terminal member 18.

The terminals 17 and 18 are respectively connected through conductors 23and 24, to two terminal pins 25 and 26. These terminal pins areconventionally mounted in a disk-shaped header 27 which is formed ofinsulating material and is secured in place, as shown, to close thebottom opening in the can 12. A third terminal pin 28 extends throughthe header 27 and is electrically connected to the upper terminal member15 by means of a resilient wave shaped connector 31 of rectangularcross-section, which also functions to bias the switching unit 14against the opposite side of the inner wall ot the coil 13, thereby toeliminate any radial play between the switching unit 14 and the coil 13.

Radial play between the coil 13 and the housing 12 is prevented by meansof a plurality of elongated resilient and folded inserts 32 which arepositioned between the coil 13 and the inner wall of the housing 12.Axial movement of the coil 13 with respect to the housing 12 isprevented by means of a washer 33 which is interposed between the sleeve21 and the lower end of the coil 13 and has one or more resilientpretensioned crimps therein for resiliently biasing the coil 13 upwardagainst the bottom surface of the oil-turned portion or the terminal 15.The terminal 15 is thus resiliently urged against an insulating disk 34positioned at the top of the housing 12. The flanged sleeve 21 issupported within the housing 12 by means of a tubular sleeve 35 which isinterposed between the sleeve 21 and the header 27. The pretensionedwasher 33 thus not only acts to force the terminal member 15 to the topof the can 12 but also acts to bias the sleeve 21 and the sleeve 35toward the header 27, thereby to prevent relative movement of theswitching unit 14 either with respect to the winding 13 or with respectto the can 12. The winding 13 is provided with a pair of input leads 36which extend through a suitable slot 37 in the sleeve 21 and arerespectively connected to terminal pins (not shown) which extend throughand are supported by the header 27.

Considering the operation of the relay of FIG. 1, let it be assumed thatthe armature 22 is normallybiased by means not visible in the drawinginto engagement with a nonmagnetic contact member 38 which is welded tothe terminal member 18 so that when no current is supplied to the coil13 the armature is positioned in the manner illustrated in FIG. 1 andelectrically connects the terminal 15 to the terminal 18. Accordingly,the terminal pins 26 and 28 are interconnected within the relay 10.

When a current of suflicient value is supplied to the windig-13 tooperate the relay 10, a magnetic field is establishd which causes fluxtraversal of the magnetic circuit. This circuit extends from the topportion of the winding 13 through the bent-over portion 15:: of theterminal member '15, through the terminal member 15 to the armature 22across the air gap between the lower portion of the armature 22 and theupper portion of the terminal member \17, through the terminal member17, across the relatively short gap to the sleeve 21, through the sleeve.21 and the walls of the can 12 back to the bent-over portion 15a of theterminal member 15. The magnetic flux which is thus caused to traversethe gap between the armature 22 and the terminal 17 causes the armature22. to pivot clockwise so that the amature 22 engages the terminal 17.When this occurs, the terminal pins 25 and 28 are interconnected and theterminal pin 26 is disconnected from the terminal pin 28. Upontermination of the supply of current to the winding 13, the

armature 22 pivots counterclockwise under the influence of the biasingforce exerted thereon to its normal position in which the terminal pins26 and 28 are connected.

Referring now more particularly to FIGS. 2 and 3, the details of asealed switching unit or cartridge 40 of the side stable type are thereillustrated. Briefly, this unit comprises a hermetically sealed housing41, preferably formed of glass, which may either be evacuated or filledwith a suitable arc suppressing gaseous medium at a desired pressurethrough a tube 42 which opens into the housing and is pinched off at itsupper end 43 after the desired atmosphere has been established in thehousing 41. A set of ferromagnetic, electrically conductive terminals44, 45 and 48 respectively extend through the upper and lower ends ofthe housing 41 and facilitate connection of the unit 40 in theelectrical and magnetic circuits of the relay. A balanced armature 46 ispivotally mounted on the terminal 44 and selectively connects it toeither of the terminals 45 and 48.

As best shown in FIGS. 2 and 3, the armature 46 is pivotally mounted ona ferromagnetic and electrically conductive supporting structure 47which is attached to the lower end of the terminal 44. The support 47comprises a pair of side members 50 which are received in suitablerecesses at the sides of the terminal member 44 andbetween the ends ofwhich extends a cylindrical pivot bar 51. The armature 46 is attached tothe support 47 by means of a cantilever type of spring or spring element52 which has its lower end secured, as by welding or the like, to thearmature 46 and may be provided with a semi-cylindrical upper endportion 53 which is adapted to engage the bar 51 and which is positionedopposite a semi-cylindrical recess 49 in the armature 46. In initiallymounting the armature 46 upon the support 47, which has previously beenattached to the terminal 44, the lefthand surface of the armature 46, asviewed in FIG. 2, is slid along the right-hand edge of the pivot bar 51so that as the off-turned upper end 54 of the spring 52 engages the bar51 the upper end of the spring 52 moves toward the left away from thebody of the armature 46 to cause the spring to ride over the bar 51until the depression 53 and the recess 49 are aligned with the bar, atwhich time the spring 52 snaps toward the right, thereby pivotally toattach the armature 4-6 to the support 47. Since the supporting posts 50and the bar 51 are formed of ferromagnetic material, they aremagnetically connected to the terminal 44. Therefore, when a magneticfield is established between the terminals 44 and 45, the armature 46pivots clockwise into engagement with the upper portion of the terminal45 thereby to establish a conductive path between the terminals 44 and45.

In the arrangement shown in FIGS. 2 and 3, the armature 46 is biasedinto engagement with the terminal 48 by means of a small cylindricallyshaped permanent magnet 57 which is mounted in a recess 58 in the rearsurface of a nonmagnetic contact 56 supported upon the terminal 48. Inorder to maximize the ratio ofthe flux path reluctance of the terminal48 to that of the terminal 45, the nonmagnetic contact 56, such, forexample, as silver, is welded to the upper end of the terminal 48. Thespacing between the contact portions of the terminals 45 and 48 isestablished by means of a nonmagnetic insulating spacer sleeve 60 whichpartially surrounds a cylindrical boss on the front side of thenonmagnetic contact member 56. The length of the spacer 60 thusdetermines the length of the air gap between the armature 46 and theterminal 45 and thus the air gap flux density required to operate therelay against the attractive force of the permanent magnet 57.

It may thus be seen that the magnet 57 biases the armature 46 in itslimiting counterclockwise position as shown in FIG. 2. If an increasedbiasing force is desired, a magnetic yoke 62 may be attached to the backof the magnet 57 so that the upper portion of the yoke 62 is inproximity to the lower end of the terminal 44 thereby to provide a lowreluctance magnetic circuit for the biasing magnet 57 which extendsthrough the yoke 62 across the gap to the terminal 44, through thesupport 47 and back to the opposite pole of the magnet 57 through thelower half of the armature.

Bounce suppression during snap return of the armature to its biasedposition is obtained by the magnetic attraction of armature 46 to thepermanent magnet 57. When the relay operates and the armature rotatesclockwise to strike the terminal 45, bounce is prevented by the strongmagnetic field which exists between the armature'46 and the contact 45to which it is directly connected.

In assembling the parts of the switching unit 4-6, the terminal 44 withthe support 47 mounted thereon and the tube 42 are first sealed into theupper end of the tubular glass housing 43. This assembly operation isperformed with the lower end .of the housing fully open. The armature 46is next inserted into the housing through the open lower end thereof andpivotally mounted upon the pivot bar 51 of the support 47 in the mannerdescribed above. The terminal 43 with the parts 56, 57 and 62 mountedthereon, and the terminal 45 are next inserted into the open lower endof'the housing 41 until they are brought into the desired positionsrelative to the terminal 44 and the armature 46. During this positioningoperation, the terminals 45 and 48 are fixedly held in their desiredrelative positions with the spacer 60 positioned therebetween. When theparts 41, 44, 45, 46, and 48 are thus correctly positioned relative toeach other and while being held in their correct relative positions, thelower end of the tubular housing 41 is sealed 01f. to complete theassembly. Finally, the interior of the housing is evacuated or filledwith a suitable arc suppressing gas through the tube 42 after which thistube is pinched off and sealed.

Referring now to FIG. 4, an alternative embodiment of a portion of theswitching unit is there shown, wherein a spring or resilient element 64is used to bias the armature into engagement with the nonmagneticcontact member 56. Since this embodiment is a modification of theswitching unit '46, similar parts are designated by like referencenumbers. As shown, the armature 46 is magnetically and electricallymounted on the common terminal 44 by means of the support 47 and thespring 52. The armature 46 is shown in its normal position in engagementwith the forward face of the nonmagnetic contact member 56 which isspaced from the magnetic terminal member 45 by means of the spacersleeve 60. A preformed spring 64 having a pretensioned resilientoilturned end portion 65 is secured at its lower end, as by spot weldingor the like, to the armature 46 and the upper end thereof bears againstthe forward face of the terminal 44 to bias the armature 46 in acounterclockwise direction into engagement with the contact member 56.It should be noted that as the armature 46 is released and pivotscounterclockwise, the off-turned portion 65 of the spring 64 slidesdownwardly against the face of the terminal 44 as the armature 46 movesinto contact with contact 56 on terminal 48.

Referring to FIG. 5 an alternative embodiment of the invention is thereshown which constitutes a modification of the spring biased armaturearrangement shown in FIG. 4. The unit of FIG. 5 is particularly suitablefor use in handling heavy switching currents and thus includes arelatively large area contact 67 which is attached as by spot welding tothe lower end of the principal body portibn of an armature 68. Thearmature 68 is pivotally supported on the terminal 44 by means of thesupport .47 and the spring 52 and the contact 67 is biased against thenonmagnetic contact member 56 by means of a biasing spring or resilientelement 76 which is attached at its lower end to the armature 68. Asshown, the armature 68 is pivoted at a point approximately at its centerof gravity, thus providing a balanced armature which requires a minimumof current in the control winding to effect operation of the relay.Also, a large area contact button 71 is mounted on the terminal member45 for electrical engagement with the contact member 67 of the armature68 when the relay is operated. The thickness of the contact member 71exceeds that of the armature 63 so that a residual gap is providedbetween the armature 68 and the terminal 45 when the relay is operated.

Referring now to FIG. 6, there is shown the upper portion of a relayembodying an alternative aspect of the invention and which includes apermanent magnet 73 disposed in the upper portion of a ferromagnetichousing or can 74 to provide a permanent magnetic field across the airgap in the associated switching unit (not shown). The magnet '73 iswedged between an upper terminal 75 and the top of the can 74 and sincethe terminal member 75 is both a part of the magnetic circuit and anelectrical conductor connected in the external switching circuit, aninsulating disk 76 is positioned between the magnet 73 and the terminalmember 75 to maintain the can '74 isolated from the electrical circuits.Therefore, by using the cartridge 40 in the embodiment of FIG. 6, therelay may be biased toward an operate or release position depending uponthe polarity of the magnet 73. More specifically, with the magnet 73polarized in one direction, more current of a particular polarity mustflow through the winding 13 to effect operation of the armature from itsreleased position to its operated position, whereas if the magnet 7'3 ispolarized in the opposite direction, a lesser current flow of the samepolarity through the winding 13 is required to overcome the normalarmature bias and effect operation of the armature to its operatedposition.

Referring now to FIG. 7, a bistable, polar switching unit 89 is thereshown. This unit comprises a set of ferromagnetic terminal members 81and 82 which extend through and are sealed to the bottom of the housing83 and are spaced apart by a nonconductive spacer sleeve 84 locatedwithin the housing. The unit 8%) also includes an armature 35 pivotallymounted on a support 86 which is attached to a common terminal memberand heel piece 87. The terminal 87 is electrically and magneticallyconnected to a ferromagnetic and conductive tube 95 which extends fromthe upper end of the housing 83 and which is pinched off and bent overat its upper end 91 to seal the housing and to provide the oil-turnedupper end of the terminal for use in conjunction with the coil andassociated structure as shown, for example, in FIG. 1. A permanentmagnet 93 is disposed outside the housing 83 between the lower portionsof the terminals 81 and 82 and is insulated from the terminal 82 bymeans of a nonmagnetic insulating spacer 94. The magnet is polarized ina direction from right-to-left and serves to bias the armature 85 ineither of its limiting positions in contact with either of the terminals81 or $2.

The unit 8% may be used in a side stable relay by using it inconjunction with the embodiment shown in FIG. 6 which includes thepermanent magnet 73. Depending upon the polarities of the magnets 73 and93, the flux densities produced by each across the air gaps between thearmature 85 and the terminals 81 and 82 will be in opposition in oneinstance and in aiding relationship in the other. Consequently, thearmature 35 is biased so as to close the latter air gap. In such a sidestable relay, properly polarized current in the relay winding overcomesthe magnetic field of the magnets 73 and 93, thereby causing the relayto operate. There is thus provided a side stable polar relay from whichthe biasing spring has been eliminated.

While the invention has been described in connection with particularembodiments thereof, it will be understood that various modificationsmay be made therein which are within the true spirit and scope of theinvention as defined in the appended claims.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

l. A method of assembling a switching unit of the type comprising aplurality of terminals respectively extending from opposite ends of atubular housing and a magnetic armature pivotally secured to one of saidterminals, the armature and at least one of the terminals includingcontact portions selectively movable into and 6 out of engagement witheach other, which comprises sealing said one terminal in one end of saidhousing, inserting the armature into said housing and pivotally securingit to said one terminal, thereafter inserting the other of saidterminals into the end of said housing opposite said one end with aportion of the other terminal overlapping and spaced from a portion ofthe armature, and sealing said other terminal to said housing.

2. The method set forth in claim 1 in which the one terminal carries apivot structure and the armature carries a fiat spring secured at oneend to the armature, and in which the step of pivotally securing thearmature to the one terminal includes inserting the pivot structurebetween the armature and the free end of the fiat spring so that theflat spring forces the pivot structure and the armature together topivotally secure these two elements.

3. A method of making a sealed switch unit from a length of glasstubing, two magnetic terminals, and a magnetic armature, the armatureand at least one of the terminals having contact portions movable intoand out of engagement with each other, which method comprises disposinga first magnetic terminal in the opening at one end of said tubing,heating said tubing to close said one end of said tubing and to rigidlymount said first terminal on said tubing, inserting said magneticarmature into said tubing through the open other end thereof, pivotallymounting the magnetic armature on said one terminal, disposing thesecond of said magnetic terminals in the open other end of said tubingwith a portion of the second magnetic terminal overlapping but spacedfrom a portion of the magnetic armature, and heat sealing the other endof said tubing to seal said other end of said tubing and rigidly mountsaid second terminal on said housing.

4. A method of making a sealed switch unit including an elongateddielectric housing having an axially extending opening with oppositeopen ends, first and second magnetic terminals, a magnetic armature, aspring element, and a pivot structure, the armature and the secondterminal having contact portions movable into and out of engagement witheach other, which method comprises the steps of securing the pivotstructure to one end of said first terminal, disposing the firstterminal in the opening at one end of said housing with the pivotstructure located within the housing and projecting toward the center ofsaid opening, heat sealing said one end of said housing to close saidend and rigidly mount said first terminal on said housing, securing saidspring element to said armature, inserting said armature into saidopening through the other open end, moving said armature to force saidpivot structure between said armature and said spring element topivotally mount said armature on said first terminal, disposing saidsecond terminal in said other open end of said housing with at least aportion of the second terminal in an overlapping but normally spacedrelation with at least a portion of the armature, and heat sealing saidother end of said tubing to close said other end and rigidly mount saidsecond terminal on said housing.

5. The method set forth in claim 4 in which the step of disposing thefirst terminal in the opening at one end of said housing includesdisposing said first terminal to one side of the axis of said opening,in which the steps of inserting and moving said armature includesdisposing said armature generally at a position extending along the axisof said opening, and in which the step of disposing said second terminalin the opening at the other open end of said housing includespositioning said second terminal on the other side of the axis of saidopening opposite said one side.

6. A method of making a sealed switch unit from a length of glasstubing, two magnetic terminals, a magnetic armature, and a generallyU-shaped pivot structure, the magnetic armature and at least one of themagnetic terminals having contact portions selectively movable into andout of engagement with each other, which method comprises securing theU-shaped pivot structure to a first magnetic terminal adjacent one endof the first magnetic terminal, disposing the first magnetic terminal inone end of the tubing with the pivot structure within the tubing,heating the one end of the tubing to seal the first terminal, insertingthe magnetic armature into the tubing through the other open end andpivotally mounting it on the pivot structure with the armature disposedbetween the bight of the U-shaped pivot structure and the adjacentportion of the first terminal, positioning the second magnetic terminalin the other end of the tubing, and heating the other end of the tubingto seal the second terminal.

7. A method of making a sealed switch unit from a length of dielectrictubing, a magnetic armature, and two magnetic terminals, one of whichcarries a pivot structure, the magnetic armature and at least one of themagnetic terminals including contact portions selectively movable intoand out of engagement with each other, which method comprises disposingthe first magnetic terminal in one end of the tubing with the pivotstructure within the tubing, sealing the one end of the tubing torigidly support the first terminal, inserting the magnetic armature intothe tubing through the other open end and mounting it on the pivotstructure with at least a portion of the armature disposed adjacent thefirst tominal, positioning the second magnetic terminal in the other endof the tubing with a portion of the second terminal spaced from andoverlapping at least a portion of the armature, and sealing the otherend of the tubing to rigidly support the second terminal.

8. A method of making a sealed switch unit from a hollow dielectrichousing, two magnetic terminals, a

magnetic armature, a resilient spring means, and a pivot structure, themagnetic armature and at least one of the magnetic terminals includingcontact portions movable into and out of engagement with each other,which method comprises mounting the pivot structure on a first magneticterminal adjacent one end of the first magnetic terminal, disposing thefirst magnetic terminal in one end of the housing with the pivotstructure within the housing, sealing the first terminal in the one end'of the housing, mounting the resilient spring means on the armature,inserting the magnetic armature into the housing through the other openend and pivotally mounting it on the pivot structure with the resilientspring means interposed between the armature and the first terminal tobias the armature, positioning the second magnetic terminal in the otherend of the housing with a portion of the second terminal spaced from andoverlapping at least a portion of the armature, and sealing the secondterminal in the other end of the housing.

9. A method of making a sealed switch unit from a length of glasstubing, two magnetic terminals, a magnetic armature, a resilient springmeans, and a generally U-shaped pivot structure, the magnetic armatureand at least one ofthe magnetic terminals having contact portionsmovable into and out of engagement, which method comprises securing theU-shaped pivot structure to a first magnetic terminal adjacent one endof the first magnetic terminal, disposing the first magnetic terminal inone end of the tubing with the pivot structure within tubing, heatingthe one end of the tubing to seal the first terminal, securing one endof the resilient spring means to the armature, inserting the magneticarmature into the tubing through the other open end and pivotallymounting it on the pivot structure with the armature disposed betweenthe night portion of the U-shaped pivot structure and the adjacentportion of the first terminal and with the resilient spring meansengaging the first terminal, positioning the second magnetic terminal inthe other end of the tubing with a portion spaced from and overlappingpart of the armature, and heating the other end of the tubing to sealthe second terminal.

References titted by the Examiner UNITED STATES PATENTS JOHN F.CAMPBELL, Primary Examiner.

1. A METHOD OF ASSEMBLING A SWITCHING UNIT OF THE TYPE COMPRISING APLURALITY OF TERMINALS RESPECTIVELY EXTENDING FROM OPPOSITE ENDS OF ATUBULAR HOUSING AND A MAGNETIC ARMATURE PIVOTALLY SECURED TO ONE OF SAIDTERMINALS, THE ARMATURE AND AT LEAST ONE OF THE TERMINALS INCLUDINGCONTACT PORTIONS SELECTIVELY MOVABLE INTO AND OUT OF ENGAGEMENT WITHEACH OTHER, WHICH COMPRISES SEALING SAID ONE TERMINAL IN ONE END OF SAIDHOUSING, INSERTING THE ARMATURE INTO SAID HOUSING AND PIVOTALLY SECURINGIT TO SAID ONE TERMINAL, THEREAFTER INSERTING THE OTHER OF SAIDTERMINALS INTO THE END OF SAID HOUSING OPPOSITE SAID ONE END WITH APORTION OF THE OTHER TERMINAL OVERLAPPING AND SPACED FROM A PORTION OFTHE ARMATURE, AND SEALING SAID OTHER TERMINAL TO SAID HOUSING.